Journal articles on the topic 'Brassica'
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1
Czajka, Agnieszka, Monika Markiewicz, Beata Kowalska, and Urszula Smolińska. "Reaction of clubroot-resistant genotypes of Brassica rapa, Brassica napus and Brassica oleracea to Polish Plasmodiophora brassicae pathotypes in laboratory tests." European Journal of Plant Pathology 158, no. 2 (August 26, 2020): 533–44. http://dx.doi.org/10.1007/s10658-020-02100-y.
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Abstract The Brassica genotypes selected for the experiments were previously found to be resistant to various Plasmodiophora brassicae pathotypes (Pb). Their interaction with pathotypes Pb2, Pb3 and Pb9 isolated in Poland was studied, using macroscopic observation for the presence of root galls, microscopic observations of P. brassicae plasmodia in the root hairs and quantitative PCR for determination of the pathogen’s quantity in plant roots and growing media. Of the Brassica genotypes studied, only B. rapa var. capitata line AABBcc was fully resistant to all the Polish pathotypes of P. brassicae. Some of the other “clubroot-resistant” genotypes tested were resistant to selected pathotypes, e.g. Brassica napus var. rapifera ‘Wilhelmsburger’ to Pb 2 and Pb3, Brassica oleracea var. capitata ‘Kilaton F1’ to Pb2 and Brassica rapa subsp. pekinensis ‘Bilko F1’ to Pb3, but were susceptible to others. B. oleracea var. capitata ‘Bindsachsener’, B. oleracea var. acephala subvar. lacinata ‘Verheul’ and B. napus var. napus ‘Mendel F1’ were moderately to highly susceptible to all Polish P. brassicae pathotypes. These results show that the classification of virulence of P. brassicae pathotypes selected in various areas differs significantly toward the same Brasssica genotypes and puts in question the practical value of pathotype classification determined with differential sets for farmers and plant breeders. Our results showed that B. rapa var. capitata AABBcc line, B. napus var. rapifera ‘Wilhelmsburger’, B. oleracea var. capitata ‘Kilaton F1’, B. rapa subsp. pekinensis ‘Bilko F1’ could be considered in Brassica breeding programmes as a source of resistance to Polish P. brassicae isolates.
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N, Poornima K., and Anita Grover. "Allele mining in Brassicas screened for A. brassicae resistance." Indian Journal of Agricultural Sciences 90, no. 6 (September 14, 2020): 1198–201. http://dx.doi.org/10.56093/ijas.v90i6.104801.
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The non-expresser of pathogenesis related gene 1 (NPR1) has been an important component of the SA/JA mediated mechanism of defence in plants. Brassicas have been major group of crop plants that are facing huge yield losses due to biotic stresses especially through Alternaria blight caused by Alternaria brassicae. Among the plethora of proteins, the NPR1 protein coding gene has been emphasised upon and an attempt has been made to isolate NPR1 alleles from different brassica species. The sequences were annotated using FGENESH and a maximum-likelihood tree was constructed using NPR1 genes from cultivated and wild brassica and also NPR1 from other crops. Understanding the genome structure of NPR1 and tagging the resistance alleles to the genomic regions of NPR1 among all species of Brassica has been aimed at in the present study.
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A.P, DHYANI, SATI M.C, and KHULBE R.D. "SEED-PLANT TRANSMISSION AND CONTROL OF ALTERNARIA SPP. IN LAHI (BRASSICA NAPUS L.) IN KUMAUN HILLS, INDIA." Madras Agricultural Journal 77, March April (1990): 137–42. http://dx.doi.org/10.29321/maj.10.a01931.
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Alternaria alternata, A. brassicao, A. brassicicola, A.radicina, A. raphant and A, tanulsalma wore detected from storage and field soods of Brassica napus grown. under different agroclimatic conditions of Kumaun Himalaya. Of them, A. alternata, A. brassicae and A. raphant wore foquently isolated from seeds, seedlings, leaves and pods and found to be responsible for seed and seedling infection. These species also caused necrosis of leaves and pods In later stogos. The pathogonicity tosts under glass house conditions proved the sorlous pathogenic bohaviour of these species. Thiram, Captafol, Dithane M-45 and Vitavax were found most satisfactory chemicals to control the infection of Alternaria spp. In seeds and other organs of Brassica napus.
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Dewage, Chinthani S. Karandeni, Coretta A. Klöppel, Henrik U. Stotz, and Bruce D. L. Fitt. "Host–pathogen interactions in relation to management of light leaf spot disease (caused by Pyrenopeziza brassicae) on Brassica species." Crop and Pasture Science 69, no. 1 (2018): 9. http://dx.doi.org/10.1071/cp16445.
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Light leaf spot, caused by Pyrenopeziza brassicae, is the most damaging disease problem in oilseed rape (Brassica napus) in the United Kingdom. According to recent survey data, the severity of epidemics has increased progressively across the UK, with yield losses of up to £160M per annum in England and more severe epidemics in Scotland. Light leaf spot is a polycyclic disease, with primary inoculum consisting of airborne ascospores produced on diseased debris from the previous cropping season. Splash-dispersed conidia produced on diseased leaves are the main component of the secondary inoculum. Pyrenopeziza brassicae is also able to infect and cause considerable yield losses on vegetable brassicas, especially Brussels sprouts. There may be spread of light leaf spot among different Brassica species. Since they have a wide host range and frequent occurrence of sexual reproduction, P. brassicae populations are likely to have considerable genetic diversity, and evidence suggests population variations between different geographic regions, which need further study. Available disease-management tools are not sufficient to provide adequate control of the disease. There is a need to identify new sources of resistance, which can be integrated with fungicide applications to achieve sustainable management of light leaf spot. Several major resistance genes and quantitative trait loci have been identified in previous studies, but rapid improvements in the understanding of molecular mechanisms underpinning B. napus–P. brassicae interactions can be expected through exploitation of novel genetic and genomic information for brassicas and extracellular fungal pathogens.
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Cheah, L.-H., G. Kent, and S. Gowers. "Brassica crops and a Streptomyces sp as potential biocontrol for clubroot of brassicas." New Zealand Plant Protection 54 (August 1, 2001): 80–83. http://dx.doi.org/10.30843/nzpp.2001.54.3779.
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Two glasshouse experiments and a field trial were carried out to evaluate the potential of brassica crops which contain high levels of glucosinolates for control of clubroot of brassicas Brassica rapa crops were grown for about 70 days in a field which was infested with Plasmodiophora brassicae In the first glasshouse experiment the leaf and stem of the plants were harvested chopped into small pieces and mixed with clubrootinfested soil in punnets Chinese cabbage seedlings were then transplanted into the punnets In the second glasshouse experiment soil samples were taken in punnets from plots where the B rapa crops had been rotary hoed and left to decompose for about three weeks Chinese cabbage seedlings were transplanted into the punnets In both experiments B rapatreated soil reduced (P
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Li, Xiaonan, Yingxia Wei, Yingmei Ma, Guizhu Cao, Siwen Ma, Tianyu Zhang, Zongxiang Zhan, and Zhongyun Piao. "Marker-Assisted Pyramiding of CRa and CRd Genes to Improve the Clubroot Resistance of Brassica rapa." Genes 13, no. 12 (December 19, 2022): 2414. http://dx.doi.org/10.3390/genes13122414.
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Clubroot, caused by Plasmodiophora brassicae, is an economically important soil-borne disease that threatens Brassicaceae crops worldwide. In recent years, the incidence area of Chinese cabbage (Brassica rapa ssp. pekinensis) clubroot disease has increased, which severely affects the yield and quality of Chinese cabbage. The resistance of varieties harboring the single clubroot-resistance (CR) gene is easily broken through by P. brassicae pathotypes. CRa and CRd, genetically identified in B. rapa, are CR genes known to be highly resistant to different P. brassicaea pathotypes. In our study, we perform the gene pyramiding of CRa and CRd in Chinese cabbages through marker-assisted selection (MAS), and develop homozygous pyramided lines. The newly generated pyramided lines exhibit greater resistance to six different pathotypes than that of two parental lines carrying a single CR gene. This study provides new CR-gene-pyramided lines for the development of clubroot-resistant Brassica varieties for future breeding programs.
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Zamani-Noor, Nazanin, and Małgorzata Jędryczka. "Pathotyping Systems and Pathotypes of Plasmodiophora brassicae—Navigating toward the Optimal Classification." Pathogens 13, no. 4 (April 11, 2024): 313. http://dx.doi.org/10.3390/pathogens13040313.
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Plasmodiophora brassicae Woronin, an obligate biotrophic soil-borne pathogen, poses a significant threat to cruciferous crops worldwide by causing the devastating disease known as clubroot. Pathogenic variability in P. brassicae populations has been recognized since the 1930s based on its interactions with Brassica species. Over time, numerous sets of differential hosts have been developed and used worldwide to explore the pathogenic variability within P. brassicae populations. These sets encompass a range of systems, including the Williams system, the European Clubroot Differential set (ECD), the Brassica napus set, the Japanese Clubroot Differential Set, the Canadian Clubroot Differential Set (CCS), the Korean Clubroot Differential Set, and the Chinese Sinitic Clubroot Differential set (SCD). However, all existing systems possess both advantages as well as limitations regarding the detection of pathotypes from various Brassica species and their corresponding virulence pattern on Brassica genotypes. This comprehensive review aims to compare the main differential systems utilized in classifying P. brassicae pathotypes worldwide. Their strengths, limitations, and implications are evaluated, thereby enhancing our understanding of pathogenic variability.
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Tasleem, Mohd, Mamta Baunthiyal, and Gohar Taj. "Induction of MPK3, MPK6 and MPK4 Mediated Defense Signaling in Response to Alternaria Blight in Transgenic Brassica juncea." Biosciences, Biotechnology Research Asia 14, no. 4 (December 25, 2017): 1469–74. http://dx.doi.org/10.13005/bbra/2593.
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ABSTRACT: Alternaria brassicae causes a highly destructive disease in Brassica juncea (Rapeseed mustard) resulting in significant yield losses. Studies of MAPK machinery components in Arabidopsis thaliana have indicated that MPK3, MPK4, & MPK6 are involved in defense response and provide resistance against various bacterial and fungal pathogens. In this study, we analyzed the expression level of MPK3, MPK4 & MPK6 in overexpressed MPK3 transgenic (BjV5) Brassica juncea at different stages of Alternaria brassicae inoculation.Expression study revealed that MPK3/MPK6 was involved in early defense response and MPK4 in late defense response. These results suggested that BjMPK3 positively regulate SA mediated defense response, which might play an important role in resistance to Alternaria brassicae in Brassica juncea.
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Elson, Marshall K., John F. Kelly, and Hugh C. Price. "EFFECTS OF BRASSICA RESIDUES ON ASPARAGUS DECLINE SYNDROME AND PLANT GROWTH." HortScience 28, no. 5 (May 1993): 473a—473. http://dx.doi.org/10.21273/hortsci.28.5.473a.
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Asparagus Decline Syndrome is caused by Fusarium oxysporum f.sp. asparagi (FOA) and Fusarium moniliforme (FM). Resistant asparagus varieties have not been found and chemicals are often ineffective against Fusarium spp. Cabbage (Brassica oleracea) residue has been shown to reduce Fusarium infection in cabbage. However, canola (Brassica napus) also reduces yields in wheat.Seven Brassicas were selected for testing in the greenhouse and field (Kale, Turnip, Glacier Canola, Global Canola, Yellow Mustard, Dwarf Essex Canola, Humus Canola). Brassica residue added to soil reduced root growth of asparagus, wheat, cress, cucumber, and cabbage seedlings upto 4 weeks. Brassicas grown in the field reduced FOA populations and the incidence of Fusarium infection, but did not inhibit plant growth. Extraction of Brassica residue did not yield any non-volatile Fusarium-inhibitory compounds.
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Sivapalan, A., and JW Browning. "Incidence of Alternaria brassicicola (Schw.) Wiltsh. on Brassica oleracea seeds." Australian Journal of Experimental Agriculture 32, no. 4 (1992): 535. http://dx.doi.org/10.1071/ea9920535.
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Samples of Brassica oleracea seed from Victoria, were tested for the presence of seed-borne Alternaria brassicicola and Alternaria brassicae. A. brassicicola was detected in 26 of 44 samples tested but A. brassicae was not detected in any. Between 24 and 37% of seed was infected, with 4-8% of infection found in the embryo tissues. Inoculation of seed with A. brassicicola resulted in loss of vigour in germinated seedlings, followed by death. The fungus retained its viability and pathogenicity on seed stored for up to 12 months. This investigation indicates that a high proportion of commercially available brassica seed are contaminated with A. brassicicola and may therefore be a primary source of disease for brassica crops in Australia.
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Chahil, Gurminder Singh, and Jagdev Singh Kular. "Biology of Pieris Brassicae (Linn.) on Different Brassica Species in the Plains of Punjab." Journal of Plant Protection Research 53, no. 1 (January 1, 2013): 53–59. http://dx.doi.org/10.2478/jppr-2013-0008.
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Abstract Biology of Pieris brassicae reared on Brassica napus, B. juncea, B. rapa, and B. carinata was studied. Adult butterflies, collected in November from the plains of Punjab, India, were sexed, paired, and released onto the four Brassica spp. in a greenhouse. In a multigeneration study (Parental, F1, and F2), the effect of the four Brassica spp. on the egg laying, incubation period and hatching percentage was assessed in a greenhouse study. Hatched larvae were collected, reared on fresh leaves of respective Brassica spp, in laboratory conditions. Data collected on larval stadia, pre-pupal and pupal durations, adult longevity, and sex ratio were assessed to understand the effects of these four species. Of the four species, B. carinata, with a shorter incubation period, higher hatching percentage, and shorter developmental periods was most susceptible. In this study, B. rapa was the most resistant species and may be recommended for further breeding programs in order to reduce the economic damage caused by P. brassicae.
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Shaw, Ranjan K., Yusen Shen, Huifang Yu, Xiaoguang Sheng, Jiansheng Wang, and Honghui Gu. "Multi-Omics Approaches to Improve Clubroot Resistance in Brassica with a Special Focus on Brassica oleracea L." International Journal of Molecular Sciences 23, no. 16 (August 17, 2022): 9280. http://dx.doi.org/10.3390/ijms23169280.
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Brassica oleracea is an agronomically important species of the Brassicaceae family, including several nutrient-rich vegetables grown and consumed across the continents. But its sustainability is heavily constrained by a range of destructive pathogens, among which, clubroot disease, caused by a biotrophic protist Plasmodiophora brassicae, has caused significant yield and economic losses worldwide, thereby threatening global food security. To counter the pathogen attack, it demands a better understanding of the complex phenomenon of Brassica-P. brassicae pathosystem at the physiological, biochemical, molecular, and cellular levels. In recent years, multiple omics technologies with high-throughput techniques have emerged as successful in elucidating the responses to biotic and abiotic stresses. In Brassica spp., omics technologies such as genomics, transcriptomics, ncRNAomics, proteomics, and metabolomics are well documented, allowing us to gain insights into the dynamic changes that transpired during host-pathogen interactions at a deeper level. So, it is critical that we must review the recent advances in omics approaches and discuss how the current knowledge in multi-omics technologies has been able to breed high-quality clubroot-resistant B. oleracea. This review highlights the recent advances made in utilizing various omics approaches to understand the host resistance mechanisms adopted by Brassica crops in response to the P. brassicae attack. Finally, we have discussed the bottlenecks and the way forward to overcome the persisting knowledge gaps in delivering solutions to breed clubroot-resistant Brassica crops in a holistic, targeted, and precise way.
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Farid, Mehdi, Rong-Cai Yang, Berisso Kebede, and Habibur Rahman. "Evaluation of Brassica oleracea accessions for resistance to Plasmodiophora brassicae and identification of genomic regions associated with resistance." Genome 63, no. 2 (February 2020): 91–101. http://dx.doi.org/10.1139/gen-2019-0098.
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Clubroot disease caused by Plasmodiophora brassicae is a challenge to Brassica crop production. Breakdown of resistance controlled by major genes of the Brassica A genome has been reported. Therefore, identification of resistance in the Brassica C genome is needed to broaden the genetic base of resistance in Brassica napus canola. In this study, we evaluated 135 Brassica oleracea accessions, belonging to eight variants of this species to identify resistant accessions as well as to identify the genomic regions associated with resistance to two recently evolved P. brassicae pathotypes, F3-14 (3A) and F-359-13 (5X L-G2). Resistance to these pathotypes was observed more frequently in var. acephala (kale) followed by var. capitata (cabbage); few accessions also carried resistance to both pathotypes. Association mapping using single nucleotide polymorphism (SNP) markers developed through genotyping by sequencing technique identified 10 quantitative trait loci (QTL) from six C-genome chromosomes to be associated with resistance to these pathotypes; among these, two QTL associated with resistance to 3A and one QTL associated with resistance to 5X L-G2 carried ≥3 SNP markers. The 10 QTL identified in this study individually accounted for 8%–18% of the total phenotypic variance. Thus, the results from this study can be used in molecular breeding of Brassica crops for resistance to this disease.
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Ashiq, Samina, Simon Edwards, Andrew Watson, Emma Blundell, and Matthew Back. "Antifungal Effect of Brassica Tissues on the Mycotoxigenic Cereal Pathogen Fusarium graminearum." Antibiotics 11, no. 9 (September 15, 2022): 1249. http://dx.doi.org/10.3390/antibiotics11091249.
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Fusarium graminearum is a globally important cereal pathogen, causing head blight in wheat, resulting in yield losses and mycotoxin contamination. Currently, triazole fungicides are used to suppress Fusarium graminearum, however, the declining effectiveness of triazoles and concerns over the safety of pesticides have led to the pursuit of safe alternative crop protection strategies such as biofumigation. In the present study, species belonging to Brassicaceae (Brassica juncea, Raphanus sativus, Eruca sativa) were assessed for their biofumigation potential against F. graminearum and the glucosinolate profile of the brassicas was determined. In Petri dishes, mycelial plugs of Fusarium graminearum were exposed to frozen/defrosted leaf discs of brassicas collected at early-leaf, stem-extension, and early-bud stages. Additionally, F. graminearum inoculum was incubated in soil amended with chopped tissues of brassicas in a closed jar experiment. Glucosinolate analysis of the leaf tissue of brassicas revealed that the total glucosinolate concentration of B. juncea ‘Brons’ increased with advancing growth stage (24.5–51.9 µmol g−1). Brassica juncea leaf discs were effective against mycelial growth, while the sinigrin content in the leaf tissue corresponded to the level of suppression. At the stem-extension and early-bud stages, B. juncea ‘Brons’ showed 87–90% suppression with four leaf discs, and 100% suppression with eight leaf discs. Brassica juncea ‘Caliente Rojo’ leaf discs collected at the stem-extension stage showed 94% inhibition with eight discs. In the closed jar experiment, each brassica species significantly suppressed F. graminearum inoculum by 41–55%. The findings suggest that the brassica species investigated in the present study could be effective in reducing the inoculum of F. graminearum in soil prior to cereal production.
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Suganda, Tarkus, and Dinda Y. Wulandari. "Curvularia sp. Jamur Patogen Baru Penyebab Penyakit Bercak Daun pada Tanaman Sawi." Agrikultura 29, no. 3 (December 6, 2018): 119. http://dx.doi.org/10.24198/agrikultura.v29i3.21645.
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ABSTRACTCurvularia sp. a new fungal pathogen causing leaf spot on the leaf of mustard greenA new diseases symptom as small spots of 1.5 - 1 mm diameter has been found on mustard green's leaf of farmer's field at Tanjungsari Regency of Sumedang. This symptom is different from those previously known incited by Alternaria brassicae and A. brassicola, Pseudocercosporella capsellae as well as by Myscosphaerella brassicicola. Although the spots are small, they are abundant and accompanied with yellowing, making these symptoms detrimental to mustard green production which has to be green and healthy. A Koch Postulate has been performed and successfully identified that the fungal causal agent was of the genera of Curvularia. Previously, curvularia leaf spot disease has never been reported on mustard green in Indonesia.Keywords: Curvularia, Leaf spots, Mustard green, Brassica junceaABSTRAKGejala penyakit baru, berupa bercak hitam berukuran diameter 0,5 - 1 mm ditemukan pada daun tanaman sawi milik petani di daerah Tanjungsari Kabupaten Sumedang. Gejala demikian berbeda dengan gejala-gejala penyakit bercak yang selama ini dikenal disebabkan oleh Alternaria brassicae dan A. brassicola, Pseudocercosporella capsellae dan Myscosphaerella brassicicola. Walaupun gejalanya berukuran kecil, namun karena jumlahnya banyak dan menyebabkan daun menguning, menjadikan gejala penyakit ini merugikan tanaman sawi yang harus hijau dan sehat. Uji Postulat Koch telah dilaksanakan, dan berhasil mengidentifikasi bahwa berdasarkan morfologi mikroskopiknya, jamur tersebut adalah dari genus Curvularia. Penyakit bercak daun curvularia, sebelumnya, belum pernah dilaporkan terdapat pada tanaman sawi di Indonesia.Kata Kunci: Curvularia, Bercak daun, Sawi, Brassica juncea
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Suganda, Tarkus, and Dinda Y. Wulandari. "Curvularia sp. Jamur Patogen Baru Penyebab Penyakit Bercak Daun pada Tanaman Sawi." Agrikultura 29, no. 3 (July 23, 2019): 119. http://dx.doi.org/10.24198/agrikultura.v29i3.22716.
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ABSTRACTCurvularia sp. a new fungal pathogen causing leaf spot on the leaf of mustard greenA new diseases symptom as small spots of 1.5 - 1 mm diameter has been found on mustard green's leaf of farmer's field at Tanjungsari Regency of Sumedang. This symptom is different from those previously known incited by Alternaria brassicae and A. brassicola, Pseudocercosporella capsellae as well as by Myscosphaerella brassicicola. Although the spots are small, they are abundant and accompanied with yellowing, making these symptoms detrimental to mustard green production which has to be green and healthy. A Koch Postulate has been performed and successfully identified that the fungal causal agent was of the genera of Curvularia. Previously, curvularia leaf spot disease has never been reported on mustard green in Indonesia.Keywords: Curvularia, Leaf spots, Mustard green, Brassica junceaABSTRAKGejala penyakit baru, berupa bercak hitam berukuran diameter 0,5 - 1 mm ditemukan pada daun tanaman sawi milik petani di daerah Tanjungsari Kabupaten Sumedang. Gejala demikian berbeda dengan gejala-gejala penyakit bercak yang selama ini dikenal disebabkan oleh Alternaria brassicae dan A. brassicola, Pseudocercosporella capsellae dan Myscosphaerella brassicicola. Walaupun gejalanya berukuran kecil, namun karena jumlahnya banyak dan menyebabkan daun menguning, menjadikan gejala penyakit ini merugikan tanaman sawi yang harus hijau dan sehat. Uji Postulat Koch telah dilaksanakan, dan berhasil mengidentifikasi bahwa berdasarkan morfologi mikroskopiknya, jamur tersebut adalah dari genus Curvularia. Penyakit bercak daun curvularia, sebelumnya, belum pernah dilaporkan terdapat pada tanaman sawi di Indonesia.Kata Kunci: Curvularia, Bercak daun, Sawi, Brassica juncea
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Jakir Hasan, Muhammad, Stephen E. Strelkov, Ronald J. Howard, and Habibur Rahman. "Screening of Brassica germplasm for resistance to Plasmodiophora brassicae pathotypes prevalent in Canada for broadening diversity in clubroot resistance." Canadian Journal of Plant Science 92, no. 3 (May 2012): 501–15. http://dx.doi.org/10.4141/cjps2010-006.
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Hasan, M. J., Strelkov, S. E., Howard, R. J. and Rahman, H. 2012. Screening of Brassica germplasm for resistance to Plasmodiophora brassicae pathotypes prevalent in Canada for broadening diversity in clubroot resistance. Can. J. Plant Sci. 92: 501–515. Clubroot disease of crucifers, caused by Plasmodiophora brassicae, poses a threat to the Canadian canola industry, and the development of resistant cultivars is urgently needed. Germplasm resistant to local pathotype(s) is the prime requirement for breeding clubroot-resistant cultivars. The objective of this study was to identify Brassica germplasm possessing resistance to P. brassicae pathotypes prevalent in Alberta. Pathotype-specific resistance was identified in the diploid species Brassica rapa (AA) and B. oleracea (CC), and in the amphidiploid B. napus (AACC). Among B. rapa genotypes, turnip was the most resistant, followed by winter type and spring type oilseed rape. The rutabaga group of B. napus, on the other hand, was homogeneous for resistance to Canadian P. brassicae pathotypes. The diploid species B. nigra (BB) also showed pathotype-specific resistance. However, the two amphidiploids carrying the B. nigra genome, B. juncea (AABB) and B. carinata (BBCC) were completely susceptible to clubroot.
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Marwa. K. Mathree and S. A. Aliwy. "MORPHOLOGICAL CHARACTERS STUDY FOR ELEVEN SPECIES BELONGS TO BRASSICACEAE FAMILY IN IRAQ." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 55, Special (January 25, 2024): 43–51. http://dx.doi.org/10.36103/ijas.v55ispecial.1884.
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This study was amied to investigate morphological characteristics of pollen grains and fruits for eleven species belonging to the tribe Brassiceae of cruciferae family, species are: Brassica rapa L , Braasica deflexa Boiss. ,Brassica nigra (L.) brassica juncea(L.), Brassica tournefortii Gouan, Brassica oleracea L., sinapis arvensis L., Hirschfeldia incana(L.) ,Savignya paraflora(Del.) ,Raphanus sativus L. ,Eurca sativa Mill., pollen grains were studied morphologically and all dimentions were recorded. The result of this study showed that most pollen grains are tricolpate ,their size varied between small ,medium and ornamentation was reticulated. The morphological study of fruits showed a contrast in the ornamentation between reticulate, smooth reticulate and rough reticulate ,it’s also varied in color, shape and dimensions.
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Kopsell, Dean A., Scott McElroy, Carl Sams, and David Kopsell. "(167) Carotenoid Accumulation Among the Diploid and Amphidiploid Brassica Species." HortScience 41, no. 4 (July 2006): 1081A—1081. http://dx.doi.org/10.21273/hortsci.41.4.1081a.
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Vegetable crops can be significant sources of nutritionally important dietary carotenoids and Brassica vegetables are sources that also exhibit antioxidant and anticarcinogenic activity. The family Brassicaceae contains a diverse group of plant species commercially important in many parts of the world. The six economically important Brassica species are closely related genetically. Three diploid species (B. nigra, B. rapa, and B. oleracea) are the natural progenitors of the allotetraploid species (B. juncea, B. napus, and B. carinata). The objective of this study was to characterize the accumulation of important dietary carotenoid pigments among the genetically related Brassica species. The HPLC quantification revealed significant differences in carotenoid and chlorophyll pigment accumulation among the Brassica species. Brassica nigra accumulated the highest concentrations of lutein, 5,6-epoxy lutein, violaxanthin, and neoxanthin. The highest concentrations of beta-carotene and total chlorophyll were found in B. juncea. Brassica rapa accumulated the highest concentrations of zeaxanthin and antheraxanthin. For each of the pigments analyzed, the diploid Brassica species accumulated higher concentrations, on average, than the amphidiploid species. Brassicas convey unique health attributes when consumed in the diet. Identification of genetic relationships among the Brassica species would be beneficial information for improvement programs designed to increase carotenoid values.
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Heinrich, Aaron, Shinji Kawai, and Jim Myers. "Screening Brassica Cultivars for Resistance to Western Oregon Clubroot Pathotypes." HortTechnology 27, no. 4 (August 2017): 510–16. http://dx.doi.org/10.21273/horttech03694-17.
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Growing resistant cultivars from the Brassicaceae family (brassicas) is an effective strategy to minimize crop loss caused by the soilborne pathogen Plasmodiophora brassicae (clubroot). However, there are many clubroot pathotypes, and genetic resistance to clubroot may be pathotype-specific. To determine which pathotypes are present in western Oregon, diseased roots were collected from five farms and identified by the European clubroot differential (ECD) set. To assess resistance to the identified pathotypes, 21 vegetable cultivars from nine crops with purported resistance to clubroot were evaluated for disease incidence and severity in field and greenhouse studies. The crops evaluated included broccoli (Brassica oleracea var. italica), cauliflower (B. oleracea var. botrytis), brussels sprouts (B. oleracea var. gemmifera), cabbage (B. oleracea var. capitata), napa cabbage (Brassica rapa var. pekinensis), pak choi (B. rapa var. chinensis), kohlrabi (B. oleracea var. gongylodes), turnip (B. rapa var. rapa), and rutabaga (Brassica napus var. napobrassica). ECD host reaction showed similar virulence among clubroot collections, and all field isolates had the same ECD pathotype designation, 16/02/30. Compared with a crop-specific susceptible control, 17 of 21 cultivars had some resistance to clubroot, and of those, 15 were highly resistant (≤15% incidence with low disease severity). This research demonstrated that western Oregon farmers have several commercially available cultivars with resistance to the dominant pathotyope in the region. However, each farmer must evaluate the suitability of these cultivars to meet consumer and industry requirements.
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Rajvanshi, Neeraj Kumar, H. K. Singh, Manish Kumar Maurya, and Rajendra Prasad. "Qualified Studies on the Pathogenic Variability of Alternaria brassicae, the Causal Agent of Blight Disease of Rapeseed-Mustard." International Journal of Environment and Climate Change 13, no. 8 (June 7, 2023): 863–69. http://dx.doi.org/10.9734/ijecc/2023/v13i82021.
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Alternaria blight of mustard caused by Alternaria brassicae is one of the major disease which causes an economic yield losses in Uttar Pradesh. Total ten (10) isolates of Alternaria brassicae were collected from different host from different states of India and characterized for pathogenic variations. The incubation period was maximum in Brassica carinata (8.82) followed by B. napus (8.70), B. nigra (7.86), B. juncea (6.00), while it was minimum in B. campestris var. yellow sarson (5.83) for all the isolates. The number of spots per leaf recorded maximum on Brassica juncea (17.66) followed by B. napus (12.66), B. nigra (9.66), B. campestris var. yellow sarson (9.00), while it was minimum in B. carinata (7.66) at 80 days after sowing (DAS). The size of spots per leaf recorded maximum on Brassica juncea (14.89 mm) followed by B. campestris var. yellow sarson (12.48 mm), B. nigra (7.89 mm), B. napus (6.96 mm), while minimum in B. carinata (5.12 mm) at 80 DAS. The number of spots on pods recorded maximum on Brassica juncea (14.66) followed by B. campestris var. yellow sarson (12.66), B. nigra (10.66), B. napus (7.66), and B. carinata (6.33) at 105 DAS. The results revealed that maximum PDI was noted on Brassica juncea (66.70) followed by B. campestris var. yellow sarson (62.99), B. nigra (60.25), B. napus (29.85), while minimum in B. carinata (24.42).
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Keim, Juan P., Mónica Gandarillas, Daniel Benavides, Jaime Cabanilla, Rubén G. Pulido, Oscar A. Balocchi, and Annick Bertrand. "Nutrient concentrations and profile of non-structural carbohydrates vary among different Brassica forages." Animal Production Science 60, no. 12 (2020): 1503. http://dx.doi.org/10.1071/an19472.
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Context Brassica forages are used in times of seasonal shortage to fulfil nutritional requirements of beef cattle, dairy cows, sheep or pigs. Although brassicas have been reported with high concentrations of readily fermentable carbohydrate, details have not been fully described and there is little information about the non-structural carbohydrate (NSC) profiles of Brassica forages. Aim The study was designed to evaluate nutrient concentrations, as well as NSC levels and constituents, of the main Brassica forages and to determine differences among varieties. Methods Five varieties of each of the four main forage brassicas (summer turnip, forage rape, kale and swede) were grown in plots and harvested for chemical analysis of the nutrient concentrations and NSC profiles of leaf and bulb (turnip and swede) and leaf and stem (rape and kale) components. Key results Brassica species differed in the amounts and types of NSC; swede had the highest concentration of NSC, mainly comprising sugars (glucose and fructose), followed by kale (with similar proportions of glucose, sucrose and fructose), turnip (with similar concentrations of glucose and starch and slightly lower fructose), and forage rape (in which starch was the main NSC). Forage chemical composition and NSC profile of plant organs varied among varieties of individual Brassica forages; for example, there were significant differences among swede varieties for concentrations of starch and sugar (total and profile) in bulbs. Conclusions Brassica forages differed with respect to quantities and types of NSC; swede had higher concentrations, mainly composed of glucose and fructose, followed by kale with similar proportions of glucose, sucrose and fructose, and turnip with NSC represented by glucose, starch and slightly lower fructose; and finally, forage rape, in which starch was the main NSC. Chemical composition, as well as NSC profile of plant organs (leaves, bulbs or stems), varied among varieties of Brassica species. Implications The approach described here has implications for ration formulation and is useful when considering the nutritional and dietary requirements of the animals of interest, because the type of Brassica, the variety and the proportion of plant organs can affect animal performance.
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BANSAL, V. K., G. SÉGUIN-SWARTZ, G. F. W. RAKOW, and G. A. PETRIE. "REACTION OF Brassica SPECIES TO INFECTION BY Alternaria brassicae." Canadian Journal of Plant Science 70, no. 4 (October 1, 1990): 1159–62. http://dx.doi.org/10.4141/cjps90-139.
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Thirty-five cultivars/strains belonging to six Brassica species were evaluated for their reaction to Alternaria brassicae under laboratory conditions. Detached leaves were wounded and inoculated with a spore suspension, and incubated at room temperature for 4 d. Lesion diameter was used as an indicator of resistance. The smallest lesions were observed in B. carinata, followed by, in order of increasing lesion size, B. oleracea, B. napus, B. campestris, B. juncea, and B. nigra. Intraspecific differences for lesion size occurred in B. napus, B. campestris, B. juncea, and B. oleracea.Key words: Brassica, Alternaria brassicae, summer rape, summer turnip rape, mustard
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Michereff, Sami J., Marissônia A. Noronha, Maria S. Xavier Filha, Marcos PS Câmara, and Ailton Reis. "Survey and prevalence of species causing Alternaria leaf spots on brassica species in Pernambuco." Horticultura Brasileira 30, no. 2 (June 2012): 345–48. http://dx.doi.org/10.1590/s0102-05362012000200027.
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Brassicaceae family comprises plant species that are very important as vegetable crops, such as the species complex Brassica oleracea and Brassica rapa. Alternaria brassicicola and A. brassicae are among the most important pathogens of Brassicaceae causing Alternaria leaf spot disease. The occurrence and prevalence of Alternaria species causing leaf spots in brassica crops in Pernambuco was acessed, as well as the existence of a possible preference by vegetable host for these pathogens. Twenty-eight fields were surveyed in the Agreste region of Pernambuco state, in the 2005 and 2006 growing seasons. In each year, 10 Chinese cabbage, six cabbage, six cauliflower and six broccoli fields were visited. In each field, 50 leaves showing at least five lesions were randomly collected. Species identification was performed taking into account morphology of the conidia that was compared with literature data. Among the two Alternaria species found, A. brassicae was found in all Chinese cabbage fields while A. brassicicola was found in all fields of cabbage, cauliflower and broccoli. Overall, A. brassicicola was more prevalent than A. brassicae. In Chinese cabbage there was predominance of A. brassicae, with mean prevalence of 91.0% and 96.5% in 2005 and 2006. On the other hand, in broccoli and cabbage there was high predominance of A. brassicicola, with mean prevalence between 95.1% and 99.8%. In cauliflower, although the prevalence has been of A. brassicicola, high frequency of A. brassicae was noted. The frequency of co-occurrence of both Alternaria species was very low. The results of this study reinforce the hypothesis of existence of host preference within species of Alternaria that cause leaf spots in brassica crops, especially when Chinese cabbage, broccoli and cabbage are considered. This information is critical to developing strategies for managing Alternaria leaf spots in Brassicaceae species.
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Miranda, José Ednilson, Luciana Cláudia Toscano, Gisèle Aparecida Bonacin, Marcos Gino Fernandes, and Karine Freitas de Farias. "IDADE DA FOLHA E RESISTÊNCIA DE VARIEDADES DE Brassica oleracea var. acephala A Brevicoryne brassicae (HEMIPTERA: APHIDAE)." BRAZILIAN JOURNAL OF AGRICULTURE - Revista de Agricultura 78, no. 3 (September 2, 2015): 347. http://dx.doi.org/10.37856/bja.v78i3.304.
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Ohshima, Kazusato, Yuka Yamaguchi, Ryo Hirota, Tamaki Hamamoto, Kenta Tomimura, Zhongyang Tan, Teruo Sano, et al. "Molecular evolution of Turnip mosaic virus: evidence of host adaptation, genetic recombination and geographical spread." Journal of General Virology 83, no. 6 (June 1, 2002): 1511–21. http://dx.doi.org/10.1099/0022-1317-83-6-1511.
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Turnip mosaic virus (TuMV), a species of the genus Potyvirus, occurs worldwide. Seventy-six isolates of TuMV were collected from around the world, mostly from Brassica and Raphanus crops, but also from several non-brassica species. Host tests grouped the isolates into one or other of two pathotypes; Brassica (B) and Brassica–Raphanus (BR). The nucleotide sequences of the first protein (P1) and coat protein (CP) genes of the isolates were determined. One-tenth of the isolates were found to have anomalous and variable phylogenetic relationships as a result of recombination. The 5′-terminal 300 nt of the P1 gene of many isolates was also variable and phylogenetically anomalous, whereas the 380 nt 3′ terminus of the CP gene was mostly conserved. Trees calculated from the remaining informative parts of the two genes of the non-recombinant sequences by neighbour-joining, maximum-likelihood and maximum-parsimony methods were closely similar, and so these parts of the sequences were concatenated and trees calculated from the resulting 1150 nt. The isolates fell into four consistent groups; only the relationships of these groups with one another and with the outgroup differed. The ‘basal-B’ cluster of eight B-pathotype isolates was most variable, was not monophyletic, and came from both brassicas and non-brassicas from southwest and central Eurasia. Closest to it, and forming a monophyletic subgroup of it in most trees, and similarly variable, was the ‘basal-BR’ group of eight BR pathotype Eurasian isolates. The third and least variable group, the ‘Asian-BR’ group, was of 22 BR-pathotype isolates, all from brassicas, mostly Raphanus, and all from east Asia mostly Japan. The fourth group of 36 isolates, the ‘world-B’ group, was from all continents, most were isolated from brassicas and most were of the B-pathotype. The simplest of several possible interpretations of the trees is that TuMV originated, like its brassica hosts, in Europe and spread to the other parts of the world, and that the BR pathotype has recently evolved in east Asia.
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Zhang, Hui, Jie Feng, Shujiang Zhang, Shifan Zhang, Fei Li, Stephen E. Strelkov, Rifei Sun, and Sheau-Fang Hwang. "Resistance to Plasmodiophora brassicae in Brassica rapa and Brassica juncea genotypes From China." Plant Disease 99, no. 6 (June 2015): 776–79. http://dx.doi.org/10.1094/pdis-08-14-0863-re.
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Clubroot disease, caused by Plasmodiophora brassicae Woronin, has become a major problem in cruciferous crops worldwide. Chinese cabbage (Brassica rapa), pak choi (B. rapa), and mustard (B. juncea) are important vegetable crops in China. Development of clubroot-resistant cultivars of these crops is urgently needed. In this study, 71 B. rapa and B. juncea genotypes from China, including cultivars and inbred lines, were evaluated for resistance to three P. brassicae pathotypes. A significant interaction was observed between the P. brassicae pathotypes and the Brassica genotypes. Pathotype 3, as defined on the differentials of Williams, exhibited the weakest virulence on all plant material. By contrast, pathotypes 5 and 6 were both highly pathogenic on most of the tested genotypes. In all, 10 of the 14 Chinese cabbage cultivars were resistant to all three pathotypes, while 4 were resistant only to a specific pathotype. Seven of eight progenies obtained from the selfing of Chinese cabbage cultivars were resistant to pathotype 3 but most were susceptible to pathotypes 5 and 6. Most inbred lines of Chinese cabbage and all inbred lines of pak choi and mustard were susceptible to all three pathotypes but their susceptibility was lower to pathotype 3 than to pathotypes 5 and 6.
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Ansari, M. S., F. Hasan, and N. Ahmad. "Influence of various host plants on the consumption and utilization of food by Pieris brassicae (Linn.)." Bulletin of Entomological Research 102, no. 2 (October 26, 2011): 231–37. http://dx.doi.org/10.1017/s000748531100054x.
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AbstractPieris brassicae (Linn.) is a destructive cosmopolitan pest of cruciferous crops. It is present wherever its host plants occur, and it is considered to be one of the most widely distributed of all the Lepidoptera. We investigated the affect of various host plants on the food consumption and utilization by P. brassicae. We quantified consumption of food, larval duration, pupal duration and weight on cabbage (Brassica oleracea var. capitata), cauliflower (Brassica oleracea var. botrytis), radish (Raphanus sativus), broccoli (Brassica oleracea var. italica) and mustard (Brassica campestris) under laboratory conditions. Insect-host relationships can be better understood by knowing the rate of food consumption, its digestibility and conversion of food eaten to body tissue. The consumption of food generally increased with the advancement of larval age. In our study we found that consumption of food was highest on radish and lowest on broccoli. The highest consumption of a particular host does not always indicate greater suitability of that host, until and unless other factors like consumption index (CI), relative growth rate (RGR), efficiency of conversion of ingested food (ECI), approximate digestibility (AD) and efficiency of conversion of digested food (ECD) are also considered. In the current investigation, factors like CI, RGR, ECI and ECD were highest on cabbage. Low body weight of pupa is associated with rapid development. On cabbage, the weight of pupa of both sexes was found lowest. Thus, from the present study, it can be concluded that cabbage is a more suitable host for P. brassicae than other host plants evaluated. Hence, on cabbage, the values of Waldbauer indices were highest and P. brassicae developed with a faster rate.
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Li, Donghui, Alison M. Ashby, and Keith Johnstone. "Molecular Evidence that the Extracellular Cutinase Pbc1 Is Required for Pathogenicity of Pyrenopeziza brassicae on Oilseed Rape." Molecular Plant-Microbe Interactions® 16, no. 6 (June 2003): 545–52. http://dx.doi.org/10.1094/mpmi.2003.16.6.545.
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Recent evidence has suggested that cutinase is required for cuticular penetration and, therefore, is essential for pathogenicity of Pyrenopeziza brassicae, the causal organism of light leaf spot disease of oilseed rape and other brassicas. In order to acquire molecular evidence for the role of cutinase in pathogenesis, the single-copy P. brassicae cutinase gene Pbc1 was disrupted by a transformation-mediated approach. Southern hybridization analysis revealed that in one mutant, NH10-1224, the disruption was due to a tandem insertion of two copies of the disruption vector into the 5′ coding region of Pbc1. In contrast to the wild type, no expression of Pbc1 was detected during in planta growth or in cutin-induced mycelium of NH10-1224 and no cutinase activity was detected in culture supernatants from NH10-1224 using pnitrophenyl butyrate as substrate. Scanning electron microscopy of Brassica napus cotyledons infected with wild-type P. brassicae confirmed that entry into the host is by direct penetration of the cuticle. In contrast, the cutinase-deficient mutant NH10-1224 failed to penetrate the cuticular layer and was unable to develop disease symptoms. This evidence is consistent with the hypothesis that Pbc1 is required for P. brassicae to penetrate the plant cuticle. Demonstration that complementation of NH10-1224 with the Pbc1 wild-type gene restores both cutinase activity and pathogenicity will be required to definitively establish that cutinase is required for successful pathogenesis of brassicas by P. brassicae.
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Stirling, G. R., and A. M. Stirling. "The potential of Brassica green manure crops for controlling root-knot nematode (Meloidogyne javanica) on horticultural crops in a subtropical environment." Australian Journal of Experimental Agriculture 43, no. 6 (2003): 623. http://dx.doi.org/10.1071/ea02175.
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In glasshouse experiments, Meloidogyne javanica reproduced on Brassica juncea, B. napus and BQMulch, a commercial biofumigant crop consisting of both B. napus and B. campestris. Although nematode multiplication rates were only 3–23% of the rate on a highly susceptible crop (tomato), they were high enough to suggest that Brassica rotation crops will increase root-knot nematode populations to potentially damaging levels in situations where temperatures do not limit nematode reproduction. A field study showed that this problem could be prevented in subtropical climates by restricting the growth of Brassica crops to June, July and August, when low temperatures limit nematode development and eggs are not produced until about 10 weeks after planting. Field and pot experiments in which M. javanica was introduced into soil following incorporation of Brassica residues failed to demonstrate a 'biofumigation' effect, possibly because the soil was too dry or the degree of tissue disruption was insufficient to maximise isothiocyanate release. Numbers of root-knot nematodes were reduced when Brassica roots, leaves and stems were incorporated into soil at 17 t DM/ha, but it is unlikely that this was due to the production of nematoxic chemicals, as large numbers of free-living nematodes multiplied during the decomposition process. From a practical perspective, these results suggest that green-manured Brassica rotation crops are unlikely to be useful for controlling root-knot nematodes on some subtropical horticultural crops that are currently fumigated for nematode control. The susceptibility of brassicas to M. javanica and the need to grow them during winter limits their potential in the vegetable industry, while difficulties in obtaining a biofumigation effect in dry soil will reduce effectiveness in non-irrigated pineapple soils. Brassicas are likely to be most useful in the ginger industry, as they can be grown during the winter break between ginger crops and fields can be irrigated before the Brassica crop is incorporated into soil.
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Farooq, Nisma, Muhammad Omar Khan, Muhammad Zaheer Ahmed, Samia Fatima, Muhammad Asif Nawaz, Zainul Abideen, Brent L. Nielsen, and Niaz Ahmad. "Salt-Induced Modulation of Ion Transport and PSII Photoprotection Determine the Salinity Tolerance of Amphidiploid Brassicas." Plants 12, no. 14 (July 8, 2023): 2590. http://dx.doi.org/10.3390/plants12142590.
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Brassica species show varying levels of resistance to salt stress. To understand the genetics underlying these differential stress tolerance patterns in Brassicas, we exposed two widely cultivated amphidiploid Brassica species having different genomes, Brassica juncea (AABB, n = 18) and Brassica napus (AACC, n = 19), to elevated levels of NaCl concentration (300 mM, half the salinity of seawater). B. juncea produced more biomass, an increased chlorophyll content, and fewer accumulated sodium (Na+) and chloride (Cl−) ions in its photosynthesizing tissues. Chlorophyll fluorescence assays revealed that the reaction centers of PSII of B. juncea were more photoprotected and hence more active than those of B. napus under NaCl stress, which, in turn, resulted in a better PSII quantum efficiency, better utilization of photochemical energy with significantly reduced energy loss, and higher electron transport rates, even under stressful conditions. The expression of key genes responsible for salt tolerance (NHX1 and AVP1, which are nuclear-encoded) and photosynthesis (psbA, psaA, petB, and rbcL, which are chloroplast-encoded) were monitored for their genetic differences underlying stress tolerance. Under NaCl stress, the expression of NHX1, D1, and Rubisco increased several folds in B. juncea plants compared to B. napus, highlighting differences in genetics between these two Brassicas. The higher photosynthetic potential under stress suggests that B. juncea is a promising candidate for genetic modifications and its cultivation on marginal lands.
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Kong, Liyan, Jiaxiu Liu, Wenjun Zhang, Xiaonan Li, Yuting Zhang, Xueyu Chen, Zongxiang Zhan, and Zhongyun Piao. "Genome-Wide Identification and Characterization of the Trehalose-6-Phosphate Synthetase Gene Family in Chinese Cabbage (Brassica rapa) and Plasmodiophora brassicae during Their Interaction." International Journal of Molecular Sciences 24, no. 2 (January 4, 2023): 929. http://dx.doi.org/10.3390/ijms24020929.
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Trehalose is a nonreducing disaccharide that is widely distributed in various organisms. Trehalose-6-phosphate synthase (TPS) is a critical enzyme responsible for the biosynthesis of trehalose, which serves important functions in growth and development, defense, and stress resistance. Although previous studies have found that the clubroot pathogen Plasmodiophora brassicae can lead to the accumulation of trehalose in infected Arabidopsis organs, it has been proposed that much of the accumulated trehalose is derived from the pathogen. At present, there is very little evidence to verify this view. In this study, a comprehensive analysis of the TPS gene family was conducted in Brassica rapa and Plasmodiophora brassicae. A total of 14 Brassica rapa TPS genes (BrTPSs) and 3 P. brassicae TPS genes (PbTPSs) were identified, and the evolutionary characteristics, functional classification, and expression patterns were analyzed. Fourteen BrTPS genes were classified into two distinct classes according to phylogeny and gene structure. Three PbTPSs showed no significant differences in gene structure and protein conserved motifs. However, evolutionary analysis showed that the PbTPS2 gene failed to cluster with PbTPS1 and PbTPS3. Furthermore, cis-acting elements related to growth and development, defense and stress responsiveness, and hormone responsiveness were predicted in the promoter region of the BrTPS genes. Expression analysis of most BrTPS genes at five stages after P. brassicae interaction found no significant induction. Instead, the expression of the PbTPS genes of P. brassicae was upregulated, which was consistent with the period of trehalose accumulation. This study deepens our understanding of the function and evolution of BrTPSs and PbTPSs. Simultaneously, clarifying the biosynthesis of trehalose in the interaction between Brassica rapa and P. brassicae is also of great significance.
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Ryan, M. H., J. A. Kirkegaard, and J. F. Angus. "Brassica crops stimulate soil mineral N accumulation." Soil Research 44, no. 4 (2006): 367. http://dx.doi.org/10.1071/sr05143.
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The impact of Brassica crops and their tissues on accumulation of mineral N in soil was examined in the field and in laboratory incubation experiments. Mineral N accumulation over the summer fallow increased by an additional 39–49 kg/ha in the top 0.10 m of soil following brassicas compared with wheat at 2 sites. At a third site there was no increase in the top 0.10 m, but this was possibly due to leaching, as a 21–39 kg/ha increase was detected over the 1.50 m profile. The accumulation of mineral N in soil collected after harvest of canola crops and incubated in the laboratory was double that of soil collected after non-Brassica crops. This outcome was not evident in soil collected when crops were flowering, only occurred in the top 0.05 m of soil, and did not persist beyond week 3 of the incubation. In further laboratory incubations using tissues from wheat and a range of brassicas matched for C : N ratio but differing in glucosinolate concentration, Brassica root tissues initially immobilised, and later released, mineral N at a greater rate than wheat root tissues. These results suggest that enhanced accumulation of mineral N following Brassica crops compared with cereal crops is unlikely to be due to biofumigation of the soil microbial community. Shifts in the composition of the soil microbial community and differences in the chemical constituents of root tissues and in above-ground crop residue inputs may instead be responsible.
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Haramoto, Erin R., and Eric R. Gallandt. "Brassica cover cropping: I. Effects on weed and crop establishment." Weed Science 53, no. 5 (October 2005): 695–701. http://dx.doi.org/10.1614/ws-04-162r.1.
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The Brassicaceae contain glucosinolates, which hydrolyze to form compounds toxic to plants, fungi, nematodes, and certain insects. Lower weed density and biomass in crops grown following incorporation of brassica cover crops suggest that they may contribute to weed management in agricultural systems. Field experiments were conducted to determine whether incorporated brassica cover crops, including canola, rapeseed, and yellow mustard, reduce subsequent weed and crop establishment; a companion paper describes separate but related field experiments that examined the influence of brassica cover crops on plant growth. Emergence rate and total emergence of sixteen weed and crop bioassay species were measured following brassica cover crops, fallow, or incorporated residues of other short-season cover crops including oat, crimson clover, and buckwheat. The bioassay species, representing a range of seed sizes, were chosen to determine whether larger seed size confers protection from residue-mediated effects on emergence. Averaged over bioassay species, brassica cover crops reduced emergence by 23 to 34% compared with fallow; emergence following brassicas was delayed by approximately 2 d. The effects of the incorporated brassica residues were similar to those of the other short-season cover crops, which reduced emergence of the bioassay species by 19 to 39% and delayed emergence by 2 d. Seed size was a poor predictor of a species' establishment. These results suggest that brassica residues are capable of delaying seedling emergence and reducing establishment, although the magnitude of their effects were comparable to other widely available cover crops.
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Smith, Brendan J., John A. Kirkegaard, and Geoff N. Howe. "Impacts of Brassica break-crops on soil biology and yield of following wheat crops." Australian Journal of Agricultural Research 55, no. 1 (2004): 1. http://dx.doi.org/10.1071/ar03104.
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Biofumigation refers to the allelopathic effects of brassicas on non-desirable soil organisms in a rotation cropping system. These effects are additional to non-hosting of root diseases, responsible for much of the break-crop effect observed in a following cereal crop. We investigated the biofumigation impacts of canola on take-all disease and rhizosphere microorganisms of following wheat crops. The biofumigation potential of the canola was tested by comparing effects of Brassica and non-Brassica break-crops and by using canola varieties with differing levels of root glucosinolates, the precursors of isothiocyanates, which are thought to be the primary biofumigant molecules released by brassicas. There was no evidence that biofumigation was related to superior growth of wheat following brassicas compared with non-Brassica break-crops, nor among the wheat crops following canola varieties with differing root glucosinolate levels. However, the break-crop effect was evident in agronomic, take-all, and some rhizosphere microbial measurements of the wheat–wheat rotations compared with fallow–wheat or break-crop–wheat rotations. Thus the break-crop effect was the primary advantage conferred by the brassicas. Any additional biofumigation effect on yield or disease was not significant in our study and does not appear to be influenced by root glucosinolate content. For broad-acre cropping with current canola or mustard varieties, and adequate grass weed control, the agronomic characteristics of canola varieties chosen should take precedence over their biofumigation potential.
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De Jong, Van, B. E. Braithwaite, T. L. Roush, A. Stewart, and J. G. Hampton. "Opportunities for developing value-added brassica seed." NZGA: Research and Practice Series 14 (January 1, 2010): 139–46. http://dx.doi.org/10.33584/rps.14.2008.3174.
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New Zealand produces approximately 5,500 tonnes of brassica seed per year, two thirds of which, valued at $13M, is exported. Black rot caused by Xanthomonas campestris pv. campestris is a common disease of brassicas, and while crop losses are not extensive in New Zealand, internationally total crop losses have been reported. Seeds are the primary source of inoculum and the ease with which this inoculum spreads means that even small traces can cause severe epidemics. Genetic resistance to black rot is a complex trait which makes breeding for resistance in brassicas challenging. The effectiveness of chemical and cultural practices is variable. Biological control with natural antagonistic microbes may provide a more effective means of controlling black rot and other pests and diseases, and create opportunities for increasing the export value of brassica seed. Current cultural practices and the potential for biological control for the management of black rot are reviewed. Keywords: biocontrol, Brassicaceae, crucifer
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Bhatiya, B. S., K. S. Bisht, Pankaj Rautela, and R. P. Awasthi. "Morphological, cultural and pathogenic variability in Alternaria brassicae, the causing agent of black spot of rapeseed and mustard." Journal of Applied and Natural Science 8, no. 2 (June 1, 2016): 840–45. http://dx.doi.org/10.31018/jans.v8i2.882.
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The study on pathogenic diversity of twenty isolates of Alternaria brassicae collected from different locations of Uttarakhand and Central Uttar Pradesh infecting Brassica species (Brassica rapa, Brassica juncea and Eruca sativa) revealed that there was a distinct difference among isolates in terms of mycelial growth, spore length, width, spore beak length and width. The average spore length varied from 21.23μm to 38.13μm with minimum of isolate AUA-19, AUA-43 i.e 21.23μm and maximum of AUA-47 i.e. 38.13μm . The isolates tested on Brassica juncea var.Varuna in green house conditions revealed that all the twenty isolates behaved differently. Among all the isolates, Brassica juncea isolates i.e. AUA-25, AUA-39, AUA-41, AUA-47, AUA-19, AUA-24, AUA-22, AUA-21, AUA-31, AUA-43 and AUA-45 from Uttarakhand, and AUP-29 from Central Uttar Pradesh can be grouped into highly pathogenic with range of Alternaria spot size i.e. 5.03-8.30mm in diameter, while isolate of Eruca sativa i.e. AUA-38 was found least pathogenic with 1.63mm in dia. and eight isolates AUA-18, AUA-20, AUA-23, AUP-28, AUA-32, AUA-33 and AUA-36 were found moderately pathogenic. This study will be useful in developing integrated management strategies of Alternaria leaf spot and breeding programs of oilseed crops (Brassica sp.).
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Billman, Eric D., S. Leanne Dillard, and Kathy J. Soder. "262 Brassicas as an alternative forage in the northeastern United States." Journal of Animal Science 97, Supplement_3 (December 2019): 90–91. http://dx.doi.org/10.1093/jas/skz258.187.
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Abstract In the northeastern United States, winter forage management has traditionally necessitated either: a) feeding conserved forages, or b) stockpiling grazeable perennial forage. Forage brassicas offer a low-cost alternative to these strategies. This project evaluated performance of different annual forage brassicas in northeastern forage production systems. Three brassicas, ‘Barisca’ rapeseed (Brassica napus L.), ‘Inspiration’ canola (B. napus L.), and ‘Appin’ turnip (B. rapa L.) were compared against ‘KB Supreme’ annual ryegrass (Lolium multiflorum Lam.) for dry matter yield and nutritive value over two autumn production seasons. Replicated plots were 5.5 × 9.1 m and seeded (brassicas at 5.6 kg/ha; ryegrass at 22.4 kg/ha) in August of 2015 and 2016 in a randomized complete block design. Four harvests occurred each year at two-week intervals following initial harvest. Statistical analyses were conducted using PROC GLIMMIX in SAS 9.4; harvest and species were fixed effects, while year and its interactions were considered random. Harvest date had no significant impact on DM yield (P > 0.05). All brassica yields (734 – 861 kg/ha) were significantly greater (P < 0.001) than annual ryegrass (344 kg/ha). This indicated brassica yield was superior under environmental stress conditions that hinder annual ryegrass growth. Nutritive value concentration suggested ryegrass had greater CP (28.1%) than the brassicas (24.2 – 25.4%) and minimal differences in net energy content (< 2%) among species (P < 0.001). However, per-area (kg/ha) values resulted in consistently greater (P < 0.001) CP (176 – 204 kg/ha), and NEL (1.2 – 1.5 Mcal/ha) than annual ryegrass (CP = 88 kg/ha; NEL = 0.56 Mcal/ha). Therefore, the greater yield potential of forage brassicas allows them to supply greater nutrient supplementation during periods of low forage availability, at a reduced feeding cost.
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Liu, Bo, Marco Antonio Fernandez, Taryn Michelle Liu, and Shunping Ding. "Investigation of Using Hyperspectral Vegetation Indices to Assess Brassica Downy Mildew." Sensors 24, no. 6 (March 16, 2024): 1916. http://dx.doi.org/10.3390/s24061916.
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Downy mildew caused by Hyaloperonospora brassicae is a severe disease in Brassica oleracea that significantly reduces crop yield and marketability. This study aims to evaluate different vegetation indices to assess different downy mildew infection levels in the Brassica variety Mildis using hyperspectral data. Artificial inoculation using H. brassicae sporangia suspension was conducted to induce different levels of downy mildew disease. Spectral measurements, spanning 350 nm to 1050 nm, were conducted on the leaves using an environmentally controlled setup, and the reflectance data were acquired and processed. The Successive Projections Algorithm (SPA) and signal sensitivity calculation were used to extract the most informative wavelengths that could be used to develop downy mildew indices (DMI). A total of 37 existing vegetation indices and three proposed DMIs were evaluated to indicate downy mildew (DM) infection levels. The results showed that the classification using a support vector machine achieved accuracies of 71.3%, 80.7%, and 85.3% for distinguishing healthy leaves from DM1 (early infection), DM2 (progressed infection), and DM3 (severe infection) leaves using the proposed downy mildew index. The proposed new downy mildew index potentially enables the development of an automated DM monitoring system and resistance profiling in Brassica breeding lines.
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Wakeham, Alison J., Gary Keane, and Roy Kennedy. "Field Evaluation of a Competitive Lateral-Flow Assay for Detection of Alternaria brassicae in Vegetable Brassica Crops." Plant Disease 100, no. 9 (September 2016): 1831–39. http://dx.doi.org/10.1094/pdis-10-15-1211-re.
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On-site detection of inoculum of polycyclic plant pathogens could potentially contribute to management of disease outbreaks. A 6-min, in-field competitive immunochromatographic lateral flow device (CLFD) assay was developed for detection of Alternaria brassicae (the cause of dark leaf spot in brassica crops) in air sampled above the crop canopy. Visual recording of the test result by eye provides a detection threshold of approximately 50 dark leaf spot conidia. Assessment using a portable reader improved test sensitivity. In combination with a weather-driven infection model, CLFD assays were evaluated as part of an in-field risk assessment to identify periods when brassica crops were at risk from A. brassicae infection. The weather-driven model overpredicted A. brassicae infection. An automated 7-day multivial cyclone air sampler combined with a daily in-field CLFD assay detected A. brassicae conidia air samples from above the crops. Integration of information from an in-field detection system (CLFD) with weather-driven mathematical models predicting pathogen infection have the potential for use within disease management systems.
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Zou, Jiawei, Shiqi Gao, Bo Zhang, Wenjie Ge, Jing Zhang, and Ruiqin Ji. "Chinese Cabbage BrCAP Has Potential Resistance against Plasmodiophora brassicae." Horticulturae 9, no. 4 (April 21, 2023): 517. http://dx.doi.org/10.3390/horticulturae9040517.
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Clubroot disease caused by Plasmodiophora brassicae Woronin (P. brassicae) has seriously influenced the production of Brassica rapa crops, but the interaction mechanism between P. brassicae and Brassica rapa is not clear. In our previous study, a differentially expressed protein, G15, was found between the roots of Chinese cabbage inoculated and un-inoculated with P. brassicae through two-dimensional electrophoresis (2-DE) and mass spectrometry, and G15 was matched with Bra011464. In this study, Bra011464 was found to have a 94% percent identity with Arabidopsis thaliana CAP, named BrCAP. The expression of BrCAP was the highest in the root compared with the stems and leaves of Chinese cabbage, and its expression in the roots of Chinese cabbage inoculated with P. brassicae was significantly higher than that in the control. The results were verified by real-time quantitative polymerase chain reaction (RT-qPCR) and in situ hybridization. Subcellular localization showed that BrCAP was localized on chloroplasts of leaf epidermal cells. To verify the function of BrCAP, it was found that the Arabidopsis thaliana mutant cap was more susceptible to infection with P. brassicae than the wild type (WT), which suggested that BrCAP has a potential role in the resistance progress of Chinese cabbage to P. brassicae.
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Thakur, Taruna, M. K. Sangha, Ramesh Arora, and M. Javed. "Effect of foliar spray of elicitors on status of defense proteins in relation to mustard aphid infestation in crop Brassica cultivars." Journal of Applied and Natural Science 8, no. 4 (December 1, 2016): 2242–48. http://dx.doi.org/10.31018/jans.v8i4.1119.
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Mustard aphid, Lipaphis erysimi Kalt., is the key insect pest of crop Brassicas causing significant reduction in crop yield. In the present study, widely grown Brassica cultivars RLC-1 (Brassica juncea) and GSC-6 (Brassica napus) were treated with elicitors salicylic acid (SA) and jasmonic acid (JA) at 0.5mM and 1mM concentration via foliar spray (given at 40 and 60 days after planting (DAP). Their effect was evaluated in terms of total soluble protein content and activities of defense proteins (peroxidase, protease inhibitor, polyphenol oxidase, amylase inhibitor and lectins) in relation to aphid infestation in leaf tissue. SA and JA application caused significant increase in activities of defense proteins as well as total soluble proteins. JA at 1mM concentration was most effective in both Brassica cultivars. The 2nd foliar spray gave a booster response. The aphid population/plant reduced significantly in both the cultivars with JA as well as SA. POD and PPO registered negative correlation with aphid population count. SA and JA foliar applications seemed effective against mustard aphid through positive modulation in activities of defense proteins.
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Lam, Anh Tung Phan, Kazunori Sasaki, Yukiko Yanagi, Shuhei Tanaka, and Shin-ichi Ito. "Intraspecific Variability and Distribution Difference within the Ribosomal Introns of the Discrete Plasmodiophora brassicae Group in Japan: A Case Study for Complex Dynamics of Intron Evolution." Agronomy 12, no. 9 (September 10, 2022): 2154. http://dx.doi.org/10.3390/agronomy12092154.
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Analysis of the ribosomal introns of Plasmodiophora brassicae populations infecting the cruciferous weed Cardamine occulta revealed the complex dynamics of size, intraspecific variability, and distribution. The results showed that P. brassicae populations from the weed have lost multiple introns in the small and large subunits of the ribosomal RNA genes. Moreover, the retained introns, despite a largely mutual share of conserved parts with the cosmopolitan strains, contained numerous novel structures. These structural differences comprise a high level of polymorphisms, such as transversion point mutations occurring at sites involving the intronic splicing sites or insertions/deletions at the binding sites. Two geographical P. brassicae populations from C. occulta carried a lengthy intron-encoded ORF and putative mobile elements established in the large subunit. A few P. brassicae populations from the Brassica crops also harbored polymorphic introns that shared common mutated motifs with the weed-affecting group. The diversity of ribosomal introns observed from those investigated populations demonstrated the genetic distinction of the P. brassicae populations from C. occulta. The genetic variations might play a key role in the adaptability of the weed-infecting populations and are more likely related to the process of pathogenesis for the cosmopolitan P. brassicae infecting the Brassica crops.
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Radunovic, Dragana, and Jelica Balaz. "Occurrence of Xanthomonas campestris pv. campestris (Pammel, 1895) Dowson 1939, on brassicas in Montenegro." Pesticidi i fitomedicina 27, no. 2 (2012): 131–40. http://dx.doi.org/10.2298/pif1202131r.
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Brassicas form the most important group of vegetable crops in Montenegro. The cabbage (Brassica oleracea var. capitata) is most commonly grown, although other brassicas, particularly kale, Brussels sprout, cauliflower and broccoli, have been increasingly produced since recently. One of the specialties of vegetable production in Montenegro is growing of collard (Brassica oleracea var. acephala), which is the simplest variety of the Brassica oleracea species and in the nearest relation with their wild ancestor - the sylvestris variety. Diseases are the main restrictive factors for successful production of these vegetables. Susceptibility of the cultivars and inadequate control often result in more or less damaged crops in some plots. Causal agents of brassica diseases, especially bacterial, have not been investigated in Montenegro until 2009. Since the symptoms observed in 2009 were ?V? shaped leaf edge necrosis and black rot of vascular tissue, it was assumed that they were caused by plant pathogenic bacterium Xanthomonas campestris pv. campestris. Samples of the infected plants were collected from different localities in Montenegro. Isolation and identification of the bacterium were performed using laboratory methods according to Schaad (1980), Lelliott and Stead (1987) and Arsenijevic (1997). Examination of chosen bacterial isolates was conducted using both, classical bacteriological methods (examination of their pathogenic, morphological, cultivation and biochemical and physiological characteristics), and ELISA test. The obtained results confirmed the presence of X.campestris pv. campestris (Pammel, 1895) Dowson 1939, on cabbage, kale, broccoli and collard in Montenegro. This is the first experimental evidence that collard is the host of X. campestris pv. campestris in Montenegro.
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Blatt, S. E., R. C. Smallegange, L. Hess, J. A. Harvey, M. Dicke, and J. J. A. van Loon. "Tolerance of Brassica nigra to Pieris brassicae herbivory." Botany 86, no. 6 (June 2008): 641–48. http://dx.doi.org/10.1139/b08-040.
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Black mustard, Brassica nigra (L.) Koch, is a wild annual species found throughout Europe and fed on by larvae of the large cabbage-white butterfly, Pieris brassicae L. We examined the impact of herbivory from P. brassicae, a gregarious herbivore, on B. nigra grown from wild seed collected locally. In greenhouse studies, the response of B. nigra to four herbivore densities in two developmental stages of the plant was quantified by measuring leaf damage, plant height, days to flowering, silique number, and seed production. Pieris brassicae readily attacked B. nigra leaves, although the timing of the attack did not affect seed production; attacked plants produced as many seeds as as nonattacked plants. Plant height was affected when plants were attacked early, but not later, in development, suggesting a connection between their belowground zone of influence and ability to regain biomass. These results demonstrate that at the herbivore densities and timing of damage studied, B. nigra tolerates folivory from Pieris brassicae through compensation.
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Ferreres, Federico, Fátima Fernandes, David M. Pereira, José A. Pereira, Patrícia Valentão, and Paula B. Andrade. "Phenolics Metabolism in Insects:Pieris brassicae−Brassica oleraceavar.costataEcological Duo." Journal of Agricultural and Food Chemistry 57, no. 19 (October 14, 2009): 9035–43. http://dx.doi.org/10.1021/jf901538j.
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Saqib, Hafiz Sohaib Ahmed, Minsheng You, and Geoff M. Gurr. "Multivariate ordination identifies vegetation types associated with spider conservation in brassica crops." PeerJ 5 (October 27, 2017): e3795. http://dx.doi.org/10.7717/peerj.3795.
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Conservation biological control emphasizes natural and other non-crop vegetation as a source of natural enemies to focal crops. There is an unmet need for better methods to identify the types of vegetation that are optimal to support specific natural enemies that may colonize the crops. Here we explore the commonality of the spider assemblage—considering abundance and diversity (H)—in brassica crops with that of adjacent non-crop and non-brassica crop vegetation. We employ spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato harbour spider morphospecies and functional groups that are also present in brassica crops. In contrast, pumpkin and litchi contain spiders not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the utility of advanced statistical approaches for identifying spatial relationships between natural enemies and the land uses most likely to offer alternative habitats for conservation biological control efforts that generates testable hypotheses for future studies.
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Ren, Li, Li Xu, Fan Liu, Kunrong Chen, Chaochao Sun, Jun Li, and Xiaoping Fang. "Host Range of Plasmodiophora brassicae on Cruciferous Crops and Weeds in China." Plant Disease 100, no. 5 (May 2016): 933–39. http://dx.doi.org/10.1094/pdis-09-15-1082-re.
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Clubroot caused by Plasmodiophora brassicae is an increasingly important soilborne disease in China. The host range of P. brassicae was investigated with 30 cruciferous plants, including 16 crop species, 9 ornamentals, and 5 weeds in field and pot-cultured conditions. In the field, 17 species from five genera produced visible galls, and these included radish, Capsella bursa-pastoris, Orychophragmus violaceus, Sinapis alba, and 13 Brassica crops. In pot-cultured conditions, an additional 13 plant species (11 genera) were determined to be hosts of P. brassicae. Five common weeds were found to be hosts of P. brassicae, including C. bursa-pastoris, Lepidium apetalum, Descurainia sophia, S. alba, and Thellungiella salsuginea. The infection of these plants was confirmed via polymerase chain reaction (PCR) with primers specific to P. brassicae. No galls were found on Matthiola incana roots in the field or in pots and no resting spores of P. brassicae were observed in M. incana roots, although P. brassicae was detected in M. incana roots via PCR. Microscopic examination revealed infection only in the root hairs of M. incana roots. These results suggested that M. incana was highly resistant to P. brassicae in China and could be developed as a bait crop. In total, 297 accessions of oilseed rape were tested in the field, and 3 accessions of Brassica napus and 1 accession of B. juncea were found to be highly resistant to clubroot disease. These resistant resources provide options for managing clubroot in P. brassicae-infested fields.
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Warwick, S. I., and L. D. Black. "Molecular relationships in subtribe Brassicinae (Cruciferae, tribe Brassiceae)." Canadian Journal of Botany 71, no. 7 (July 1, 1993): 906–18. http://dx.doi.org/10.1139/b93-102.
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Restriction-site variation for 17 endonucleases was compared in the large single-copy region of the chloroplast genome in 74 taxa of the genera Brassica, Coincya, Diplotaxis, Eruca, Erucastrwn, Hirschfeldia, Raphanus, Sinapidendron, Sinapis, and Trachystoma (subtribe Brassicinae, tribe Brassiceae, Cruciferae). A total of 422 restriction-site mutations was observed, with 228 (54%) showing variation among taxa. Phylogenetic analyses indicated a clear division of the subtribe into two main lineages designated here as Rapa–Oleracea and Nigra. Polyphyly was evident in five genera (Brassica, Diplotaxis, Erucastrum, Sinapis, and Trachystoma) as indicated by their placement in both lineages and (or) further separation into groups within a lineage. The genera Coincya, Hirschfeldia, and Sinapidendron were monophyletic within the Nigra lineage, as were Eruca and Raphanus in the Rapa–Oleracea lineage. Four major groups were recognized within each lineage. The lowest levels of chloroplast DNA divergence were observed among taxa belonging to the same cytodeme or crossing group and were highest for Brassica rapa and Brassica oleracea versus Brassica nigra at 2.10–3.91% and 2.00–3.78%, respectively. The chloroplast DNA data were incongruent with traditional taxonomic circumscription of 5 of the 10 genera but concordant with other data sets that support the close genetic relatedness of all 10 genera. Key words: Brassica, Coincya, Erucastrum, Sinapidendron, Trachystoma, chloroplast DNA restriction-site variation.
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Koike, S. T. "Broccoli Raab as a Host of Alternaria brassicae in California." Plant Disease 81, no. 5 (May 1997): 552. http://dx.doi.org/10.1094/pdis.1997.81.5.552a.
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In the fall of 1996, commercial plantings of broccoli raab or rappini (Brassica rapa subsp. rapa) in the Salinas Valley, Monterey County, were damaged by a disease previously unreported in California. Symptoms consisted of small (7 to 8 mm in diameter), circular to oblong, brown to light tan leaf spots that contained characteristic concentric rings. An Alternaria sp. having conidia with prominent beaks and spores produced singly or in chains of two was consistently observed on and isolated from the host. Conidia from naturally infected broccoli raab measured 144.5 to 194.5 × 22.2 to 30.6 μm (beak length ranged from 33.3 to 75.0 μm). The isolates were identified as Alternaria brassicae (Berk.) Sacc. (2). Pathogenicity was confirmed by culturing five representative isolates on sterilized 20% V8 juice solution for 10 days under a 12-h light/12-h dark cycle, filtering the suspensions through cheesecloth, obtaining spore concentrations of 30,000 conidia per ml, and spraying suspensions onto 6-week-old seedlings of broccoli raab cv. Spring Raab. Plants were incubated in a humid chamber for 48 h and then maintained in a greenhouse. After 5 to 7 days, leaf spots similar to the original symptoms developed on all inoculated plants. The pathogen was reisolated and identified as A. brassicae. Control plants sprayed with distilled water remained symptomless. The inoculation test was repeated and results were the same. Because of the extensive plantings of cole crops in the Salinas Valley, isolates from broccoli raab were inoculated onto two sets each of broccoli (Brassica oleracea subsp. italica cv. Greenbelt), Chinese cabbage (Brassica campestris subsp. pekinensis cv. Cha-Cha), and Japanese mustard (Brassica campestris subsp. nipposinica cv. Mizuna), using the method described above. After 5 to 7 days, similar leaf spots developed on all inoculated plants and A. brassicae was reisolated and identified. Control plants sprayed with distilled water remained symptomless. This fungus does not appear to be a pathogen specific to particular cole crops in this area (1). For California, this is the first report of black spot caused by A. brassicae on commercially grown broccoli raab. References: (1) S. T. Koike. Plant Dis. 80:822, 1996. (2) E. G. Simmons. Mycotaxon 55:55, 1995.